Ar. tetrahydro-naphthyl thioureas



UNITED STATES PATENT OFFICE 2,055,608 AR. TETRAHYDRO-NAPHTHYL THIOUREAS Herbert A. Labs and Arthur L. Fox, Wilmington,

Del., assignors to E.

Delaware No Drawing. Application November 3, 1934, Serial No. 751,283

3 Claims. (Cl. 260-125) This invention relates to ar. tetrahydronaphthyl thioureas and methods the same.

An object of this invention is tetrahydro naphthyl chemical compounds. vide a method for preparing such compounds.

for preparing to provide ar.

thioureas which are new A further object is to pronew chemical Still other objects are to advance the art. Other objects will appear hereinafter.

These objects may be accomplished in accordance with the present invention which comprises reacting water soluble salts of acids and ar. tetrahydro-naphthylamines with alkali thiocyanates. The resulting products are ar. tetrahydro-naphthyl thioureas which pounds.

are new chemical com- These new chemical compounds are valuable intermediates for the preparation of safety paper chemicals and dyestuffs.

In order to more clearly illustrate our invention and the preferred mode of carrying the same into effect, the following example is given:

Example I The following ingredients were placed in a one liter flask and refluxed for 16 hours.

parts ar. tetrahydro beta naphthylamine, 300

parts water,

44: parts concentrated hydrochloric thalene. The amount of hydroch ployed is just enough to bring the loric acid emsolution to the edge of congo acidity. The solution remained clear for about one hour and then as the thiourea began to became turbid form. After 16 hours,

the flask was cooled rapidly with stirring and fied in the form of small shot-like yield was 100 parts of crude materi the ar. tetrahydro-beta-naphthyl thiourea solidicrystals. The al. The crude Pont de Nemours & Del., a corporation of material was recrystallized from 16 parts of alcohol giving a finely crystalline product melting at 174.6 to 1'75.8 C.

Analysis Theory N 13.21% N=13.5 8% S 15.27% S==15.52%

Ar. tetrahydro-alpha-naphthylamine may be employed in the place of the ar. tetrahydro-betanaphthylamine to produce the corresponding thiourea. Also, other acids which form water soluble salts with ar. tetrahydro-naphthylamines such as the hydrobromic, hydrofluoric, sulphuric, etc. may be employed in place of the hydrochloric. Other alkali thiocyanates such as the sodium and potassium thiocyanates may be employed in place of the ammonium thiocyanate. Also, other inert solvents or reaction media such as dilute alcohol, dilute acetone and the like may be employed in place of the water.

While we have disclosed the preferred form of our invention and the preferred mode of carrying the same into efiect, it will be readily apparent to those skilled in the art that variations and modifications may be made therein, particularly in the relative proportions thereof without departing from the spirit of our invention. Accordingly, the scope of our invention is to be limited solely by the appended claims construed as broadly as is permissible in view of the prior art.

We claim:

1. An unsubstituted ar. thiourea.

2. Ar. tetrahydro beta-naphthyl thiourea.

3. Ar. tetrahydro alpha-naphthyl thiourea.

HERBERT A. LUBS. ARTHUR L. FOX.

tetrahydro naphthyl 

